Section for komatsu d20,21 and similar grey market dozers

[mitch504]

Link worked great, thanks very much.
Mitch

 

[bubbagoat]

The new link worked great. Thanks

Bubba

 

[PonyExpress94]

Does anyone own a Shop Manual for the 4D95S-W-1 Engine that is used in -6 and (I believe) -7 models? It is referred to as the 95 Series Engine Shop manual. I am trying to find out what the part number for that manual is. I have found a manual that I can purchase that is printed in 1998 but I need to know if that printing will still be accurate for a 1987 era engine that I need to repair and rebuild.

 

[chael04_2004]

I have created this account for my father. He has a Komatsu d21p and had a few questions I hope to find some answers on here. If anyone can give me some answers that would be great thank you in advance. First question is The dipstick found on the floodboard in the front, what is it for and what type of fluid? Second question The dipstick found in the back on the floorboad what is it for and what type of fluid? Third question is On the tracks close to the rear there are plugs on each side what are these for and what goes in them? I have read other post about the dipsticks and viewed the information but I was unsure if you use regular motor oil or is there a specific type. Again I hope this makes sense and someone can help thank you much. Michelle.

 

[joemorgan]

the front one is for the transmission, SAE30w motor oil, the one at the rear is the bevel gear, SAE30w motor oil, the plugs on the rear case, the final drives, SAE30w motor oil, you will find a plug on the inside bottom of each final drive, this is the drain plugs, the hydraulic system takes either SAE10w, SAE10w-30 or SAE15w-40 your choice on these, these machines use automotive motor oil for everything, hope this helps.

 

[chael04_2004]

thank you

the front one is for the transmission, SAE30w motor oil, the one at the rear is the bevel gear, SAE30w motor oil, the plugs on the rear case, the final drives, SAE30w motor oil, you will find a plug on the inside bottom of each final drive, this is the drain plugs, the hydraulic system takes either SAE10w, SAE10w-30 or SAE15w-40 your choice on these, these machines use automotive motor oil for everything, hope this helps.

Thank you so much this was very helpful. So glad I found this website. Thanks again and God bless.

 

[RRRancher]

Would it be ok to change the cranckcase oil, etc. by using a vacuum suction pump down the filler tubes so as not to have to crawl under the dozer?

I personally wouldn't do that as I don't think it would get all the stuff that might be sitting down by the drain plug. I just changed the oil on my D20A-6 the other day and was amazed at how easy it was. One thing that helped was that I drove the dozer over the area I was going to park it for the oil change, then scraped the area between the two track marks and pushed and pulled the dirt onto the two track marks, making two small, long, and narrow hills. Then I drove it up on these hills, laid cardboard underneath it and found that I had lots of room to crawl under and pull the cover plate and the drain plug. I was done in less than 30 minutes time. It took longer to get the oil filter off and replaced than it did to drain the pan.

 

[Terry Valentine]

Thanks - New member - had a d21s-5 for about 12 years now - repaired nearly everything on it until today I pulled the transmission apart because it was slipping. Many of the friction plates surfacing have broken apart. I have been using SAE30w oil, but what we buy today is very different from what it was back in 1984 when this machine was made. Lots of other additives ? Has there been any debate on which is the best oil that will not damage the friction plates ? BTW - the transmission is not all that hard to dissasemble - getting it all back together may be a challenge.

Next .. all you from US and Canada that have trouble finding parts - email me what you need - here in Malaysia we still have thousands of small, but excellent, workshops - example Rebonded my brake shoes for about USD30 - relined all my steering cluthes for about USD50 - parts to rebuild my engine for about USD250 - remanufactured the final drive pinion to original hardness USD120 + all undercarriage bits

Thanks for a great forum ....

 

[Terry Valentine]

"Pushed on that arm" - I use a 6 foot crowbar - it takes a lot of force - the clutch pack is normally engaged - there are some heavy duty springs inside the clutch pack. It may be that you are not getting sufficient oil pressure in the slave cylinder - there is a square head bleed valve on the back of the slave cylinder - open a bit and with engine running push the valve on the side of the slave cylinder closed to allow oil in - the same as pulling the steering arm. Make sure all the air is out and a good flow of oil then tighten the bleed valve. As it works on one side and not the other then your oil pump (at front of transmission) should be ok.

Operation - pull steering arm - valve on slave cylinder depresses - oil is allowed into slave cylinder - pushes piston against arm - arms depresses springs inside clutch pack - which opens the pack allowing free rotation. Keep pulling steering arm and your brake should work.

 

[Michaelp]

I'm new here and not sure if this where im supposed to post? I have a question hopefully someone can help me out. I recently bought a d20a and it's been sitting a long time. When I try to steer right it lugs the engine down but won't stop the track from turning. I think that the brake is working like it should but the right clutches are stuck causing it to choke the engine down. If this is my problem then what do I need to take apart to check? Thanks for any help.

 

[Terry Valentine]

I'm new here and not sure if this where im supposed to post? I have a question hopefully someone can help me out. I recently bought a d20a and it's been sitting a long time. When I try to steer right it lugs the engine down but won't stop the track from turning. I think that the brake is working like it should but the right clutches are stuck causing it to choke the engine down. If this is my problem then what do I need to take apart to check? Thanks for any help.

This sounds right - first get the workshop manual - dblaneyfan posted a link to one on the 20/1/2012. It is pretty straight forward to remove, but a knuckle buster getting at the bolts that hold the clutch pack in, then lifting it straight up. See how you go - ask when need help ! Probably rusted together - pull out clutch pack - dismantle - clean and check - put back in. There is a drain plug under the case - make sure that there is no water inside the case - this could be the cause of seizing.

 

[Terry Valentine]

At high RPM you are overcoming the loss of friction in the transmission clutches. These are either worn (spec is 3mm - 2.7mm) or like mine the friction plates have partly broken apart. Drain the transmission oil, pull out the filter and the filter housing and check whether there are little black pieces of friction plate in the bottom of the case. If you need to rebuild the transmission, download manual and read carefully before pulling transmission out - it sounds difficult but is not really that hard. I am currently doing mine - 6 of the 8 plates have lots of pieces missing - but it still ran !! Luckily I have complete rebonding facilities here - so cost should be minimal. I will let you know when I get all the seals and Orings as well.

 

[Terry Valentine]

If one track stops then it is your track clutch, if both stop then it is the clutches in the transmission. The transmission has four clutch packs inside - it uses two for each action - forward one, forward two, reverse one, reverse two. See workshop manual for a great writeup. So - one of two (at least) of your transmission clutches is borderline at least. But best to check them all - you will need to pull it all apart anyway. These clutch packs are simple multiplate (2 or 3 depending on model) packs, with the wear really only occuring on the friction material - so if you can get them locally rebonded then the cost is small - just two oil seals and some O rings are needed as well.

 

[sparke]

D-21

How do you adjust clutch.

 

[cropduster69]

Hey guys, on my D31E, I have a grease leaking recoil spring assembly and want to install new seal and packing. Do I understand correctly from other posts, that this can be accomplished without having to disturb or fool with the actual spring and its containment?

thanks in advance

 

[cropduster69]

also, does anyone know the length of the spring when fully relaxed?

 

[joemorgan]

selling my dozer

I have a 1988 D20A-6 in good condition that I am going to be selling, 2900hrs on a working meter, if interested, contact me at [email protected] for photo's and info.

 

[Terry Valentine]

There is a screw thread and lock nut at the top of the bar that compresses the clutch pack that the clutch hydraulic piston acts on. Although in 12 years I have not had to adjust a steering clutch. I have replaced the friction discs. But see whether you can adjust it, or maybe your hydraulic pressure is not sufficient to push the lever, or your slave cylinder is faulty (leaking). Also check that your control levers are depressing the piston (small) on the slave cylinder completely. If this is not fully depressed then the slave cylinder will not be getting enough oil pressure to act on the clutch.

 

[Terry Valentine]

Yes, remove the track, and then just pull out the idler wheel with its' hub and the piston attached. Then you will see the seal inside the cylinder.

 

[sparke]

Thanks Terry
It acts like its froze it was working fine last time I used it sit for 6 months and now one side won't pull and lever on that side will not go down.
how big of a job is it to replace clutch.
sparke